The guy that put the septic system in was rushed - had to finish off in the dark holding a small flashlight. Meant he didn't get the levels right so there is lots of water running to the septic tank. The horrible clay meant the back fill didn't really fill the hole around the septic tank so there is a collapsing ring around the tank = water trap. There is an external pump but if it fails or can't keep up - the tank will float up out of the ground. He even put the outlet from the external pump uphill from the septic (using the trench to the irrigation area) so part of what is pumped out just runs straight back down. The weather forecast was for heaps of rain - so I dug out the drain around the tank and reluctantly diverted water to run under the cabin instead of into septic tank. The external pump is working frequently - hope it doesn't fail.
These are all from a single punnet (6 cell) I bought from Bunnings - heaps in each cell so I spread them out - they looked terrible at first.
Months after I had tank installed they finally came back to install the water level - there was a part missing when they first installed. Big relief since I had no idea how close I was to running the pump dry.
I helped to move the platform frame from Jeff's place (left) where he welded it together to the unit and connect it. Still need to put the other side posts in and floor - it's designed to hinge on the shed side so can be folded down when not in use, hopefully to avoid it becoming a playground for the local kids (note community hall in background). There is a hole in the middle where a stretcher can be lowered.